The White House will release a report Tuesday that will fundamentally change the way many criminal trials are conducted. The new study from the President’s Council of Advisors on Science and Technology (PCAST) examines the scientific validity of forensic-evidence techniques—DNA, fingerprint, bitemark, firearm, footwear and hair analysis. It concludes that virtually all of these methods are flawed, some irredeemably so.
Americans have long had an abiding faith in science, including forensic science. Popular TV shows like “CSI” and “Forensic Files” stoke this confidence. Yet the PCAST report will likely upend many people’s beliefs, as it should. Why trust a justice system that imprisons and even executes people based on junk science?
Only the most basic form of DNA analysis is scientifically reliable, the study indicates. Some forensic methods have significant error rates and others are rank guesswork. “The prospects of developing bitemark analysis into a scientifically valid method” are low, according to the report. In plain terms: Bitemark analysis is about as reliable as astrology. Yet many unfortunates languish in prison based on such bad science.